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<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>P25：2-21</title>
    <script type="text/javascript">
        window.onload = function () {
            myFunction();
        }

        function myFunction() {
            alert("你好，这是一个简单的JavaScript程序！")
        }
    </script>
</head>
<body>

</body>
</html>